1. Field of the Invention
Priority is claimed on Japanese Patent Application No. 2010-172217, filed Jul. 30, 2010, the content of which is incorporated herein by reference.
The present invention relates to an image forming apparatus.
2. Description of Related Art
In electro-photographic image forming apparatuses such as copying machines or printers according to the related art, residual toner adhered to a photosensitive drum, an intermediate transfer belt, or the like is cleaned by a cleaner and is collected into a dedicated waste toner container. When the waste toner container is fully filled with the waste toner, the waste toner container is replaced. The waste toner container has a near detection sensor and a full detection sensor attached thereto, where the near detection sensor is configured to detect that the waste toner container is nearly fully filled with the waste toner and the full detection sensor is configured to detect that the waste toner container is fully filled with the waste toner. When the near detection sensor detects that the waste toner container is nearly fully filled with the waste toner, a user is urged to replace the waste toner container via a notification unit such as a touch panel. Further, when the full detection sensor detects that the waste toner container is fully filled with the waste toner, the image forming operation is stopped. The waste toner collection device as described above is disclosed, which gradually detects the amount of the waste toner collected by the waste toner container by using a plurality of sensors.
Hereinafter, the position where the near detection sensor is to be attached is referred to as the near position, and the state in which the waste toner container is nearly fully filled with the waste toner and which is detected by the near detection sensor is referred to as near detection. Further, the position where the full detection sensor is to be attached is referred to as the full position, and the state in which the waste toner container is fully filled with the waste toner and which is detected by the full detection sensor is referred to as full detection.
In the related art, when the distance between the near position and the full position is close, there is a possibility of erroneous detection in which full detection occurs immediately after near detection or in which full detection occurs before near detection. Therefore, the image forming operation may be stopped immediately after the request of the replacement of the waste toner container or the image forming operation may be stopped without the request of the replacement of the waste toner container.